Method and apparatus for well drilling and testing



D. B. GRABLE Dec; 22, l1953 METHOD AND APPARATUS FOR WELLDRILLING AND TESTING f2 Sheets-Sheet l Filed Feb. 16, 1952 INVENToR. zx/Mu m UEE. rurali? 4.

BOA/@VAN B. Gens/ 5,

lnllmlw umm TTQNE Fdo 2M 35 v., 7 w 72.@ a a w m M fr n w 7 w m r ,9 I o A v, i E A ..\4. n

Dec. 22, 1953 D. B. GRABLE METHOD AND APPARATUS FOR WELL DRILLING AND TESTING Filed Feb. 16, 1952 2 sham-sheet 2 muv- Patented Dec. 22, 1953 UNITED STATES PATENT OFFICE METHOD AND APPARATUS FOR WELL DRILLING AND TESTING Donovan B. Grabl, Long Beach, Calif. Application February 16, 1952, Serial No. 271,927

' 15 Claims. (cl. 255- 1.4')

This invention has to do wlth improved sys- 1"" tems for drilling, testing and producing oil wells, and yis directed particularly to novel methods and apparatus characterized by the employment of a dual pipe or drill string made up ofV an inner pipe section contained vwithin and spaced from an outer pipe section so that drilling circulation or other fluid flow may be maintained downward ly within one of the pipe passages and upwardly' to the ground surfacethroughfthe other pipe passages. VWell drilling systems employing such composite pipe stringsare also dealt with in my copending applications Serial No. 139,655, filed January 20, 1950, on Method and Apparatus for Drilling Wells, and Serial No. 243,626, nled August 25, 1951, on Method and ApparatusEmploying Compressed Gas'for DrillingWells.

One of the primary advantages in the use of the dual pipe string as a fluidconductor, is that it permits the maintenance of fluid circulationu. as to and from a drill bit, while isolating the well" 'boreabove the workingvicinity of the bit from relatively free -fromontamination by materials normally distributed throughout the exposed surface of the formation by vconventional mud or drilling iiuid circulation whichr iiows in contact ,with and throughout the extent of the well bore. The present invention is concerned in one of. Aits major aspects with well testing and fluid dis placement from the well, by new methods and equipment benefiting also as' to accomplishment .f and appurtenant equipment, useable for either or 2 ably near the bottom of the hole by a fluid pressure expansible packer carried by the string and communicable with the pipe string, and preferably the inner pipe for expansion by fluid pressure therein. Above the packer the inner pipe contains vertically spaced ports through which aflifting fluid may flow from one into the other of the pipe section passages, and ordinarilyin downward sequence to progressively displace to the ground surface liquid standing in or entering the string from thek well below the packer. Preferably the ports normally are closed by individual valves which may be selectively opened as in downward sequence, to admit the lifting fluid, preferably air or other gas, to the discharge passage. Typically, and preferably, compressed air is delivered to the inter-pipe space for discharge through the sequentially opened ports into the inner pipe which is in communication with the zone to be tested. As a result of the progres. sive displacement of liquid from the inner pipe, it is possible to remove from above the test Zone substantially all liquid initially present, and thereafter to displace from the test zone true samples of the'materials therein, or of the fluids directly entering the zone from the "formation, uncontaminated with liquids or solids from other As will appear, the invention presents the important accomplishment of providing a drill string bothdrilling and testing apparatus. Following i a period of drilling to the depth of a particular of their objectives, from confinement to the dual vpipe string of fluid ow into and out of the Well. Specifically contemplated are situations of pressurized circulation or fluid displacement (l) into and out ofia lower or bottom zone of the well, and (2) through an upper extent of the drill `string assembly, while the. lower portion of the string is packed voff from the formation, this positively isolating the circulation and imposed pressure effects from the formation above the packer. i 'e H y l As illustrative of a typical operation contemplated by the invention, its objective may beto test the formation 'or fluid composition or .now rates into a bottom section ofthe well bore. Preparatory to sample taking or flow movement,

the formation is packed on at a location preferformation to be investigated, the string and as-y sociated parts may be converted to testing purposes, after which the equipment may be restored Ato drilling conditions, all without having to pull the string or undertake other than simple operations.

All the various features and objects of the invention, as well as the details of certain typical embodiments, will be more fully understood from the following detailed description of the structure and operation of the illustrative equipment shown by the accompanying drawings, in which: Fig. 1 is a general view showing the apparatus positioned for operation in a well;

Fig. 2 is a sectional enlargement of the gooseneck swivel head;

Fig. 3 is a fragmentary enlargement of the bottom portion of the drill string showing the packer and the bit below;

Fig. 4 is a fragmentary enlarged crosssection taken on line 4 4 of Fig. v1 through one vof the sleeve valves; Y i

I Fig. illustrates the valve of Fig. 4 in open position, and Fig. 6 is a cross section on line 6-5 of Fig. l.

eferring first to the general showing oi" Fig. `l, the dual section pipe string le is shown to be lowered in the well bore l l and to include an upper Kelly stand I2 extending through the casing head I3 and rotary table i4 which operates in the usual manner to rotate the strong Iii. The head I3 has appropriate pipe connections I5 and I5 for the introduction or escape of liquid or gaseous fluids from the well bore at the outside of the pipe string. The latter is vertically supported by the swivel head il having the usual type of bale I6 to be hooked to the traveling block, not shown.

Referring to Figs. 3 and 4, the pipe string ifi) comprises an outer pipe I3 and an inner pipe 20, the pipes being annularly spaced to provide a ilow passage 2l which preferably corresponds in cross sectional area to the bore or flow passage 22 in the inner pipe. The stands of the respective pipes are interconnected by threaded internally flush, externally upset joints 23 and 24, and beyond the joints the stands are interconnected by circularly spaced welded inserts 25. The structural details of the dual pipe string, their method of interconnection and the advantages of particular types of threaded joints, are more specically dealt with in my copending applications referred to hereinabove. At its lower end the pipe string carries a suitable form of drill bit 25 having a passage 2'! communicating with the pipe string passage 2| and communicating through passages 23 and 29 with the inner pipe bore 33. Thus fluid circulation may be maintained through the bit passages 2?, 23 and 29 from the pipe string passage 2l into passage Sil, or reversely from passage 3i? into the outer passage 2I.

For more detailed description of the swivel head assembly illustrated in Fig. 2, reference may be had to my rst led application Serial No. 139,- 655. scribe the assembly il as comprising a tubular body 3l containing a stem 32 rotatable within bearing 33 and connected at 34 to the Kelly l2. At its upper end the stern 32 is rotatable lwithin its packed joint at 35 with gooseneck 35 connected to the hose 3l. The upper belled end 20a of the inner pipe 2B receives and is rotatable at 33a within the lower end of a second gooseneck 36a connected to the hose Sla. The gooseneck 36 has an axially alined branch 38 which normally is plugged, but upon removal of the plug receives a flexible line passing attachment 39. The later may be in the nature of a lubricator comprising a tubular body 4l) threaded into the branch 38 and containing a rubber packer or wiper adapted to seal about the ywire line 42 which may be run into the pipe string as later described. As will be understood, the gooseneck 36 communicates through passage 43 with the interpipe passages 2i, and gooseneck V35a communicates through its bore lili with the passage 33 in the inner pipe 2U.

The pipe string Ill carries at kits lower end, and preferably at a location just above the bit 26, a fluid pressure expansible packer generally -indicated at 46. This packer may be oi any of various known types adapted to be expanded in response to internally applied pressure, into engagement with the wall of the well bore 1I.

Merely as illustrativa'the packer is shown to comprise a rubber sleeve 41 having clamped'conne- For present purposes it will suffice to de-V ment at its upper and lower ends about the outer pipe I9 within ttings 48 which in turn are clamped rigidly to the pipe. Fluid pressure is communicable to the interior 49 of the packer from the pipe string, and preferably from within the inner pipe 20 through one or more tubular valve bodies 50 terminating within the inner and outer vpipes and containing a ,ball check 5l normally held by coil spring 52Y against its seat 53. Below the check valve, the inner pipe 20 contains a seat 54 having an opening 55 adapted to be closed temporarily by a ball check 56 which isdropped down into place within the pipe string.

Above the packer 46 the inner pipe 2G carries at suitable intervals, say in the order of 200 feet spacing, a series of. selectively openable Valves generally indicated at 5l, see Figs. 4 and 5, which may be of any appropriate type adapted to establish temporary communication between the pipe string passages 'L' I and 22 at the location of the valves. Typically each valve assembly 5,7 .is shown to comprise a tubular vertically movable sleeve valve 58 adapted to seat downwardly against shoulder Eiland containing ports'movable into and outof registration with port 5l. Upward displacement of the valve from its normal position of seating against shoulder` 53. (in which passages B and SII are in eiect closed) is resisted by coil spring 32 confined 4between the topvof the valve and the pipe shoulder 63.

Each valve may be selectively opened `by a suitable tool, such as I have illustrated at 6.4, run down in the pipe string through the llubricator 39 on the wire line42. The tool 64 typically is shown to comprise a yoke 65 connectedat yt6 to the wire line and carrying a rpair of grapple dogs 6'! pivoted at '58 on the'yokeand so Ymounted as to tend to lie outwardlyagainstthe pipe. When lowered to the Fig. 5 position, the dogs 5.7 are receivable within the sleeve recess 69 and engageable against shoulder 10 so thatnan upward pull on the wire line raises the valve. Dogs 61 are releasablefrom engagement l.with .the shoulder by tubular go-devil 'II which may` bedropped downfon the wire line to engage 'the innerends 69a of the dogs and thus swing the latter inwardly away from vrthe shoulder v'70.

In considering the operation and methods of using the equipment, assume first that normal drilling operations are in progress with the packer 46 ldeflated and the rdrill string rotated by the drive transmitted to the kelly from the rotary table I4. A suitable circulating fluid such as an oil-or water base mud, or a gaseous uid such as air, is discharged 'from `hose "31 `through passages 43-and -2I to the drill bit26 wherein the 'liuidV ilows inwardly from passage 2^'I `through passage 2B into the bit bore 29, entraining the cuttings as theyare severed from the formation by the bit, for'removal in-the fluid stream rising through the inner pipe 20 and discharging through the gooseneck VA36 to hosef.31. `During such circulation a liquid column may be maintained in the wellibore I I outside the drill :string at a level 'suiiicientlyhigh to imposeatzthe :bit-a hydrostatic pressure, such as'to require fthe circulation through fthedrill:stringpassages :to .be conned substantially entirely to ow withinthe bit, i. e., through passages 28. AThe function of the Well'liquid column thus isprimarilyto'main- 4tain an essentially=static column v'of 'lluid somesof which lprogressively feeds into .the'zbit.l to beinduced along with the ycuttings andxcirculation fluid, into the :dischargezstream :going ;tof.the

old surface. nyliquidmake up to valve V in line I6, any desired pressure may be p maintained within the well.

Assume next that drilling has progressed into a formation or sand requiring test or identification to determine its composition or `relation to other structures in the formation. The invention now affords a means of obtaining a Vtrue and uncontaminated sample of the sand or other formation at the particular depth of the bit. First the packer 46 is expanded by dropping the ballA check 56 onto its seat 54 and pumping or compressing fluid down within the inner 'pipeV 26 at a pressure sufficient to unseat the check valve Yand discharge the 'fluid'r into the interior 49 of the packer sleeve 41. Upon expansion of lthe packer into the Fig. 3 Ibroken line condition 41a of engagementA with the'well bore wall, the fluid pressure transmission is discontinued and valves 5| seat to maintain the expanding condition of the fluid inside the packer.- Fluid circulation then may be conducted downwardly Vthrough passage 2| and up through theinner pipe bore h 3U to displace the ball check 56 out through the gooseneck 36. Y

l The valves 51 then may be operated in downward sequence to introduceair or other gas into the inner pipe for the purpose of progressively displacing all liquid standing in the inner pipe above the lowermost valve, while simultaneously displacing any liquid well inflow above that location, which may occur during the operation. B-y lowering thetool4 64 on wire line 42 into the uppermost valve 51,y the latter may be Vlifted to bring ports 60 and 6| into registration and permit ow from passage 2|V into the inner pipe passage of compressed air being discharged into the string from hose 31.

above the valve is displaced out through hose 31.

.Thereaften the tool 64 is lowered to open the valve next below, whereupon the air circulation is maintained to displaceV to the ground surface the liquid above the valve, and so on as the valves are successively open in downward sequence, and successive segments of vthe liquid column are displaced Vout of the inner pipe. With the lowermost valve positioned just above the packer 46, it is thus possible to remove from the pipe string substantially all liquid and the sands Vand cut- --tings Aentrained therein. By dropping the gov devil 1|, the dogs 61 may be collapsed to permit the tool to be withdrawn from the string.

A suitable fluid, preferably a gas such as air, now is circulateddown through passage 2| and the bit passages to displace sand or other loose formation material from within the bit up The invention further contemplates the testing of bottom holeconditions by appropriate instrumentation run down through the inner pipe section after sealing about the drill string -by ex- The air ow is main tained until the liquid within the inner pipe pansion of the packer as previously described, and either before or after displacement of the well fluid from the pipe stringY by the described sequential operation of the latir'valves.y Referring to Fig. 3, I have indicated at I an instrument which may be run down on a wireline through the inner section lof the string to -the bottom of the hole after `expansion of the packer, andy for example after displacement of the liquid from the inner pipe and following removal of rthe tool 64 and ball check 56. The instrument I may be of any of the appropriate lknown types for indicating or recording bottom hole pressures, and as will be apparent, with the packer expanded to seal oif against the formation aboveythe pressure re'- corded or indicated by the instrument affords a true determination ofthe actual bottom `hole pressure, independently of any uid column pres lsure outside the drill string and above the packer.

The instrument indicated at I mayinstead be regarded as a diagrammatic showing of an electrical logging instrument which may be operated under similar conditions for electrically surveying the bore wall formation at any location below the packer. Regarding the instrument I as -any known or appropriate type of electrical'logging instrument, the survey may be made with the instrument position as shown, or the `pipestring may be raised and the instrument run',l out through the bit into the open hole. As Vwill be understood from the foregoing, with the formation and any fluid column sealed off by and above the packer, and particularly afterremoval of any liquids from the pipe stringwhich forl any vreason might adversely affect the survey-the electrical logging operation may be conducted in the sealed-0H bottom of the hole free from any interference which ordinarily might be encounter-ed in the absence of the seal off. y

I claim: f

1. Oil well equipment comprising a pipe string including an inner ypipe and an outer pipe spaced therefrom, an expansible packer carriedvby said outer pipe near the lower end thereof and adapted to be expanded against the well bore wall, means for expandingv said packer, said pipes -being in communication with each other and with the well at a location beneath said packer, a-port in said inner pipe providing communication between said inner and outer pipes at a location spaced'above said first-mentioned location, a valve controlling fluid flow through said po-rt,and means for actuating said valve. ,l f e 2. Oil well Vequipment yas recited in claim 1, including a plurality of said ports in the inner pipe at a plurality of vertically spaced locations above said first location, valv-es controlling fluid flow through said ports, and means for individually and selectively controlling said valves.4

3. Oil well equipment Ias recited in claim 1, including a drilling tool carried by the lower end of said string and containing passages through which said inner and outer pipes are in communication with each other and with the well.

4. Oil well equipment as recited in claim 1 in which said packer is adapted for expansion outwardly by fluid pressure communicated thereto from Within the string.

5. Oil well equipment as recited in claim 1 in which said packer is adapted for expansion outwardly by fluid pressure, and including passage means for communicating fluid pressure from said inner pipe to the packer, and means within said inner pipe below said passage means for closing off fluid flow downwardly through the Vsaid inner and outer -pipes,valves controlling. fluid Vflow through said ports, and `means for individuallyl and selectively controlling said valves. Y 7.- Oil well equipment Vas recited in claim G,V including a drilling .tool carried by the lower end ,of

.said V'string andspaced beneath said ports and lcontaining passages through which-said pipes are .-in communication V with each other. and with the well.

`8..,Oi1 well equipment as recited in claim '7, in

which said packer `is adapted for vexpansion .against the bore wall by uid pressureand including passage means for communicating fluid pressure from the inner pipe to the packer, means `withinsaid inner pipe below said passage means for closing oi uid flow downwardly through the inner pipe while fluidl pressure is communicated Ato..fthepacker, and check valve-means for prevent-- ing reverse fluid ilow throughsaid-passage means from the packer to said inner pipe to maintain the packer in inflated condition.

f9. -Inoil well equipment of the type comprising Vvagdrill str-ing including spaced inner and outer pipes andin which fluid is circulated downwardly within one of saidipipesand then upwardiy within the other; the improvement comprising an ex- A .pansble packer carried by said youter pipe near the lower end thereof and adapted to be expanded byuid pressure against the well bore wall, passage means for communicating iiuid pressure from the inner pipe to the packer, means within said inner pipe below said .pass-age means for `closing off fluid flow downwardly through the inner pipe vwhile fluid .pressure is communicated `to the packer, and-valve vmeans for preventing reverse fluid ow through said passage .means from the/'packer to said inner pipe to maintain the packer inA inated condition.

10. A'combination as recited in claim Q, including means for, opening said valve means to deflate the-packer.

l1. A combination as recited in claimf9, includingfa port in said innerpipe providing communication between said inner and outer pipes ata yloca-tion spaced above said passage means, a valve .controlling fluid flow through said port, and 1 means forV actuating said valve.

12. The method of displacing a liquid vfrom within. a double walled string of well tubing containing two, passages, which comprises applyinga 0 Number gas under pressure tothe upper end of one 4of said passages, and sequentially vproviding communication between said two pass-ages at 4Vertica-lly spaced locations, whereby the liquidwill beprogressively displaced from the string passages by the gas.

13. The method vasrecited in claim 12, in which `said gasisappliedunder pressureto thespace between the 'two walls of said tubing, and forces the liquid upwardly within the inner wall.

14. The method oftesting a well comprising lowering into the well a double walled string .of well tubing containing two passages one about the other, closing thespace between said sti-ing and the well bore wall at a location near the lower end of the string,y applying` a gas underv pressure to the upper end of one of said passages, sequentiallyr providing communication between said two -passages at vertically spaced locations, whereby well liquid contained in the string passages will be progressively displaced therefromby said gas, and thentesting thewell While said space between the string and bore wallfremains closedat said location.

15. The method of displacing ra liquid from within, .and a 4formation sample upwardly through, a double walled string of we ll pipe positioned within a well and containing two passages one aboutthe other communicating withl each other and with the well through al drilling tool carried at the lower end of the string, that comprises closing the space `betweenlthe. string and the well bore wall near the lower `end of the string, applying a compressed gas. to the upper end. of one of said passages, sequentially providing. communication between said two passages at vertically spaced locations abov'e said tool, wherebyv the liquid will be progressively displaced fromY the string passages by said gas, and then circulating said gas downwardly through one of said passages and to said tool and then upwardly through the other passage to the surface ciV the earth to elevate a sample of the earth formationvto the surface bysaid circulation.

DONOVAN B. GRABLE.

References Cited'in the -file of this patent UNITED YSTATES PATENTS Name Date Durbrow July 3, 1,888 Durbrow Jan. 11, l1898 Ivens Sept. 17,1901 Steele July 28, 1925 Steele Oct. 1-2, 1926 Waltermre v June 27, 1939 Linney Aug, 6, 1940 Norris Feb, 11, 1941 Smith Sept. 11, 1951 

